blown motors??
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lilchampro1
- Posts: 0
- Joined: Wed Mar 10, 2021 10:41 pm
blown motors??
ya i was just wondering what happens to the dales crank when they go is it the bearing, rod , can anyone tell me what exactly happens??? and when do u kno this will happen any signs
Sounds like you are talking about the crank bearing failure within the rod....here goes
the bearing race starts to wear into the pin. The metal flakes that are produced float around inside the bearing until flushed by new oil but in the meantime chew up the rod surface. This looks like pitting when you pull it apart. These metal flakes also make their way into the oil that hits the piston and sleeve. Well, these small flakes will do a little damage to the skirt, but not much.
As the pin starts to wear a groove is formed in the top half of the pin, from the compression stroke pushing down on it. Well with that groove the bearing race sits further into it causing the race to wear faster and faster.
Keep in mind that everything above is on a running motor! It will be running great at this point. Then after more wear and an unknown amount of time KABOOM! The race fails.
When this happens the metal race jams up into the rollers and stops it in its tracks. I have seen good cranks pressed apart and have a nice groove which ruins the crank and I have seen a completely seized crank where the rollers and race fallout into 100 pieces when pressed apart. Very nasty stuff.
Now, when it fails and right before there are very large metal flakes being pumped and they will scar the crap out of your skirt and sleeve. The over all result is a trashed crank, trashed piston and sleeve, possibly trashed oil pumps, metal in the frame......Nasty stuff for $100 upgrade that could have helped prevent it.
And for those out there that doesn't see this as a problem.....
the bearing race starts to wear into the pin. The metal flakes that are produced float around inside the bearing until flushed by new oil but in the meantime chew up the rod surface. This looks like pitting when you pull it apart. These metal flakes also make their way into the oil that hits the piston and sleeve. Well, these small flakes will do a little damage to the skirt, but not much.
As the pin starts to wear a groove is formed in the top half of the pin, from the compression stroke pushing down on it. Well with that groove the bearing race sits further into it causing the race to wear faster and faster.
Keep in mind that everything above is on a running motor! It will be running great at this point. Then after more wear and an unknown amount of time KABOOM! The race fails.
When this happens the metal race jams up into the rollers and stops it in its tracks. I have seen good cranks pressed apart and have a nice groove which ruins the crank and I have seen a completely seized crank where the rollers and race fallout into 100 pieces when pressed apart. Very nasty stuff.
Now, when it fails and right before there are very large metal flakes being pumped and they will scar the crap out of your skirt and sleeve. The over all result is a trashed crank, trashed piston and sleeve, possibly trashed oil pumps, metal in the frame......Nasty stuff for $100 upgrade that could have helped prevent it.
And for those out there that doesn't see this as a problem.....
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lilchampro1
- Posts: 0
- Joined: Wed Mar 10, 2021 10:41 pm
motor
so what update helps prevent this, is there anyway to make last longer
Sure, take the crank out and have the junk stock bearing replaced with a Z400 bearing. We don't know 100% that it is a permanent fix for the cranks but so far I think they are wearing just like any other crank out there. I don't know of a single crank failure due to the Z400 bearing.
This is not the easiest update to perform but in my opinion it is the most or second most important update to do. I won't run a stock crank without it.
To do this you have to pull the crank, then have it rebuilt. Can't do that yourself but at the most you are out $125 for the rebuild including the bearing + little bit for gaskets and rings. Not bad compared to the +$500-$1000 if the crank goes kaboom.
This is not the easiest update to perform but in my opinion it is the most or second most important update to do. I won't run a stock crank without it.
To do this you have to pull the crank, then have it rebuilt. Can't do that yourself but at the most you are out $125 for the rebuild including the bearing + little bit for gaskets and rings. Not bad compared to the +$500-$1000 if the crank goes kaboom.
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lilchampro1
- Posts: 0
- Joined: Wed Mar 10, 2021 10:41 pm
crank
who makes aftermarket cranks and with the z 400 bearing it will still wear /? does lighting or balancing the crank help who do u recommend builting motors thanks again
balancing the crank of course helps but the stock bearing was just not as good as the Z400 is. The Z400 bearing has 2 more rollers contacting the pin and rod surface and the cage is a better material. And yes, the bearing will wear out eventually. But nothing like what the stocker does.
As for aftermarket cranks there is only 1, Falicon. Timbo is rebuilding blown cranks but thats no easy task and its still at least $400 shipped.
If you have an older billet rod on the crank your balance is pretty good, just replace the bearing.
As for recomending the engine work, all the main people on here are good. Doug, Tim, and others depending on your location. But, with a little patience you could do it yourself. Maybe if you are close to someone they could help you do it for yourself and then in the future you could work on it by yourself.
Where are you located?
As for aftermarket cranks there is only 1, Falicon. Timbo is rebuilding blown cranks but thats no easy task and its still at least $400 shipped.
If you have an older billet rod on the crank your balance is pretty good, just replace the bearing.
As for recomending the engine work, all the main people on here are good. Doug, Tim, and others depending on your location. But, with a little patience you could do it yourself. Maybe if you are close to someone they could help you do it for yourself and then in the future you could work on it by yourself.
Where are you located?
So the "crank failures" are really bearing failures?
You wouldnt happen to know the bearing part numbers for both the originall one and the z400 replacement?
Reason I ask is that maybe there is something about them that would or could show why it was happening (load or speed ratings, internal clearence or fit etc).
Or maybe I should just be asking if its known why the pin and bearing start wearing on each other?
You wouldnt happen to know the bearing part numbers for both the originall one and the z400 replacement?
Reason I ask is that maybe there is something about them that would or could show why it was happening (load or speed ratings, internal clearence or fit etc).
Or maybe I should just be asking if its known why the pin and bearing start wearing on each other?
YUPPO!! The crank failures are the main rod bearing in the crank. It just gets shredded.
I don't know the numbers off hand. may be able to find them at some point. One area that some have looked at why they hit the pin is that there is a small groove right next to the crank half the pin is on. If the bearing slips into there even a little the stock bearing will rub on the pin. I don't know for sure about this but it would make sense. Now, with the Z400 there is more rollers hitting the pin giving less wear on the cage.
To prevent to much wear on my stock crank I will be rebuilding the crank every 100 hours or so. I know that sounds like alot but I am anal about preventative maintanance.. That and replacing the valves, just normal yearly maintanance on a race machine.
I don't know the numbers off hand. may be able to find them at some point. One area that some have looked at why they hit the pin is that there is a small groove right next to the crank half the pin is on. If the bearing slips into there even a little the stock bearing will rub on the pin. I don't know for sure about this but it would make sense. Now, with the Z400 there is more rollers hitting the pin giving less wear on the cage.
To prevent to much wear on my stock crank I will be rebuilding the crank every 100 hours or so. I know that sounds like alot but I am anal about preventative maintanance.. That and replacing the valves, just normal yearly maintanance on a race machine.
Now this is getting interesting.
So for some unknown reason the lower rod bearing is getting caught into the groove for the locating pin? Yes its a question
If you can get those bearing numbers it would be great, and I would offer what ever I can find as to the differences between them that could be part of the problem.
I see you mention that the replacement bearing has more rollers in it, and that leads to my wanting to check out original ones specs since bearings with more rollers tend in general to have a higher rpm limit from those rollers being smaller than the ones in a bearing with fewer but larger rollers that normally would have a higher load capacity.
So for some unknown reason the lower rod bearing is getting caught into the groove for the locating pin? Yes its a question
If you can get those bearing numbers it would be great, and I would offer what ever I can find as to the differences between them that could be part of the problem.
I see you mention that the replacement bearing has more rollers in it, and that leads to my wanting to check out original ones specs since bearings with more rollers tend in general to have a higher rpm limit from those rollers being smaller than the ones in a bearing with fewer but larger rollers that normally would have a higher load capacity.